Liposuction, also known as lipoplasty, involves the insertion of a hollow cannula into adipose or fatty tissue beneath the skin, usually accompanied by the injection of a fluid typically containing a local anesthetic and a vasoconstrictor and, optionally, an antibiotic, known as tumescent liposuction, to mechanically extract globules of fat by applying a vacuum to the cannula and sucking the fatty tissue into the cannula through a side vacuum port near the cannula's distal end.
The distal edge of the side vacuum port is sharp and, when globules of fat are drawn by suction into the vacuum port and the cannula is rapidly pulled backward, the sharp edge cuts off the globules of fat, which are evacuated by suction through the cannula into a collection bottle. However, when the cannula is rapidly pulled back, the sharp distal edge of the port also cuts blood vessels running through the fatty tissue, which can cause significant bleeding and increase the risk of an infection.
For example, an anesthetic such as lidocaine at a dosage of about 35 mg per kilogram of body weight, or a vasoconstrictor, such as epinephrine at a dosage of about 0.7 mg per kilogram of body weight, are commonly used in tumescent liposuction procedures to anesthetize and help separate tissues by constriction during the liposuction procedure. An antibiotic may be added to reduce the risk of an infection.
In the late 1990s, ultrasound energy was introduced to facilitate the fat removal process by liquefying globules of fat, but complications tempered the initial enthusiasm of many practitioners. Recently, laser energy to melt and liquefy fat has been introduced, which also has the benefit of less bleeding, as the laser energy can coagulate blood vessels in the fatty tissue, which are broken or cut during the liposuction process.
The use of laser energy to lyse (disrupt) the membranes of adipocytes (fat cells), soften and liquefy the released fat, called laser lipolysis, is presently performed in three different laser fat removal procedures. In the most preferred laser fat removal procedure, laser energy is transmitted from a laser through an optical fiber disposed within a hollow liposuction cannula. The optical fiber extends up to a side port in the wall of the liposuction cannula near its distal end. The port may or may not have a sharp proximal edge.
As adipose (fatty) tissue is drawn by suction into the side port in the liposuction cannula, laser energy is emitted straight ahead, lyses the membranes of the fat cells and softens or liquefies the released fat, which is drawn through the liposuction cannula into a collection bottle by vacuum. Most of the blood vessels in the fatty tissue which are broken or cut are coagulated (cauterized) by the laser energy. The released fat is evacuated into a collection bottle by vacuum. If the side port in the liposuction cannula does not have a sharp distal edge, this fat removal process is less traumatic than a conventional liposuction procedure.
In some laser liposuction procedures the distal end of the liposuction cannula is open or partially open, and the optical fiber extends up to open or partially open distal end of the liposuction cannula. As the cannula is advances and/or withdrawn, laser energy lyses fat cells opposite the distal end of the cannula and the released fat is drawn into the cannula and evacuated by suction. Again, blood vessels broken or cut during the procedure are coagulated (cauterized) by the laser energy.
Another benefit of the use of laser energy in a liposuction procedure is the fat is quickly removed and little is able to be absorbed into the bloodstream, avoiding an increase in the cholesterol and triglyceride levels in the patient's bloodstream.
In the second laser fat removal procedure, the optical fiber, optionally contained in a metal or rigid plastic cannula with an open distal end for better handling, without suction, is used to transmit laser energy straight ahead from the distal end face of the optical fiber to lyse the membranes of fat cells, soften and liquefy the fat. The optical fiber is inserted through a trocar puncture or surgically created opening and is advanced and withdrawn one or more times, and is withdrawn almost to the insertion point, and is then advanced and withdrawn at a series of different angles, like the ribs of a fan.
At the end of the laser procedure, the optical fiber is removed from the body, and a conventional liposuction cannula is introduced to evacuate the softened or melted fat. However, performing these procedures separately takes longer than the preferred procedure described above, and some of the softened or liquefied fat may be missed by the liposuction cannula and left in place, some of which may be absorbed into the bloodstream, which may raise the level of cholesterol and triglycerides in the bloodstream.
In the third laser fat removal procedure, the optical fiber again may be contained in an outer metal or rigid plastic cannula for ease of handling. The optical fiber is introduced and laser energy is emitted straight ahead from the distal end face of the optical fiber to lyse the membranes of the fat cells and soften or liquefy the fat, as described above. No suction or vacuum is used in this procedure. After removal of the optical fiber is removed from the body, some or most of the fat may be absorbed in the bloodstream and delivered to the liver, where it is said to be metabolized in the same manner as fat from the diet. It is not known if the larger volume of cholesterol and triglycerides in the bloodstream arising from this procedure is deleterious or not.
Laser energy emitted directly ahead from the flat distal end of a conventional optical fiber does not greatly diverge, so many insertions of the optical fiber at various angles are required. Also the same pattern of insertions is required, if a liposuction cannula is introduced to remove the melted fat, during or following the fat cell lysing procedure.
While the relative safety and efficacy of these three procedures, to our knowledge, has not been published, cosmetic surgeons and dermatologists experienced in using one or more of these procedures must evaluate which of them will best serve the needs of each individual patient. If the amount of laser energy is properly controlled, most blood vessels in the fatty tissue, which are cut or broken during the procedure, are coagulated by the laser energy, and little bleeding beneath the skin occurs.
At wavelengths of 300 to 400 nanometers (“nm”), for example, from an excited dimer or “excimer” laser at 308 or 351 nm, the laser energy is highly absorbed by molecular bonds, causing fat cell membranes to be disrupted and the released fat to be melted. At wavelengths of 1400 to 1500 nm and 1800 to 2300 mu, for example, from a diode laser at 1470 nm, a Thulium:YAG laser at 2000 nm or a CTH:YAG laser at 2100 nm, the laser energy is highly absorbed by water, which is almost instantly heated, disrupting the membranes of the fat cells and melting the released fat.
At wavelengths of 400 to 1400 and 1500 to 1800, the laser energy is minimally absorbed by pigments, for example hemoglobin in blood or melanin, until a temperature sufficient to disrupt the membranes of fat cells and melt the released fat.
In this patent application, our objective is to maximize the ability to lyse fat cells and vaporize tissue by combining improved devices for delivering laser energy with an optimal method of use of such devices to accomplish the desired purpose: safe, uniform and effective lysing of fat cells and melting of the released fat.
It is a further objective of this invention to provide a laser energy delivery device and a method of its use to more safely and effectively lyse the membranes of a greater number of fat cells beneath the dermis and soften or liquefy a greater volume of the released fat over a wider area in a more uniform manner than is possible with a straight-ahead firing optical fiber. It is another objective of this invention is to do so without endangering the dermis at 12 o'clock and blood vessels, nerves and other delicate structures at 6'o clock.
The present invention attains these objectives in a safe and effective manner.